• Greg Spencer's avatar
    Remove 'must be non-null' and 'must not be null' comments from material. (#134991) · a1e49be2
    Greg Spencer authored
    ## Description
    
    This removes all of the comments that are of the form "so-and-so (must not be null|can ?not be null|must be non-null)" from the cases where those values are defines as non-nullable values.
    
    This PR removes them from the material library.
    
    This was done by hand, since it really didn't lend itself to scripting, so it needs to be more than just spot-checked, I think. I was careful to leave any comment that referred to parameters that were nullable, but I may have missed some.
    
    In addition to being no longer relevant after null safety has been made the default, these comments were largely fragile, in that it was easy for them to get out of date, and not be accurate anymore anyhow.
    
    This did create a number of constructor comments which basically say "Creates a [Foo].", but I don't really know how to avoid that in a large scale change, since there's not much you can really say in a lot of cases.  I think we might consider some leniency for constructors to the "Comment must be meaningful" style guidance (which we de facto have already, since there are a bunch of these).
    
    ## Related PRs
    - https://github.com/flutter/flutter/pull/134984
    - https://github.com/flutter/flutter/pull/134992
    - https://github.com/flutter/flutter/pull/134993
    - https://github.com/flutter/flutter/pull/134994
    
    ## Tests
     - Documentation only change.
    Unverified
    a1e49be2
popup_menu_theme.dart 8.96 KB
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:ui' show lerpDouble;

import 'package:flutter/foundation.dart';
import 'package:flutter/widgets.dart';

import 'material_state.dart';
import 'theme.dart';

// Examples can assume:
// late BuildContext context;

/// Used to configure how the [PopupMenuButton] positions its popup menu.
enum PopupMenuPosition {
  /// Menu is positioned over the anchor.
  over,
  /// Menu is positioned under the anchor.
  under,
}

/// Defines the visual properties of the routes used to display popup menus
/// as well as [PopupMenuItem] and [PopupMenuDivider] widgets.
///
/// Descendant widgets obtain the current [PopupMenuThemeData] object
/// using `PopupMenuTheme.of(context)`. Instances of
/// [PopupMenuThemeData] can be customized with
/// [PopupMenuThemeData.copyWith].
///
/// Typically, a [PopupMenuThemeData] is specified as part of the
/// overall [Theme] with [ThemeData.popupMenuTheme]. Otherwise,
/// [PopupMenuTheme] can be used to configure its own widget subtree.
///
/// All [PopupMenuThemeData] properties are `null` by default.
/// If any of these properties are null, the popup menu will provide its
/// own defaults.
///
/// See also:
///
///  * [ThemeData], which describes the overall theme information for the
///    application.
@immutable
class PopupMenuThemeData with Diagnosticable {
  /// Creates the set of properties used to configure [PopupMenuTheme].
  const PopupMenuThemeData({
    this.color,
    this.shape,
    this.elevation,
    this.shadowColor,
    this.surfaceTintColor,
    this.textStyle,
    this.labelTextStyle,
    this.enableFeedback,
    this.mouseCursor,
    this.position,
    this.iconColor,
    this.iconSize,
  });

  /// The background color of the popup menu.
  final Color? color;

  /// The shape of the popup menu.
  final ShapeBorder? shape;

  /// The elevation of the popup menu.
  final double? elevation;

  /// The color used to paint shadow below the popup menu.
  final Color? shadowColor;

  /// The color used as an overlay on [color] of the popup menu.
  final Color? surfaceTintColor;

  /// The text style of items in the popup menu.
  final TextStyle? textStyle;

  /// You can use this to specify a different style of the label
  /// when the popup menu item is enabled and disabled.
  final MaterialStateProperty<TextStyle?>? labelTextStyle;

  /// If specified, defines the feedback property for [PopupMenuButton].
  ///
  /// If [PopupMenuButton.enableFeedback] is provided, [enableFeedback] is ignored.
  final bool? enableFeedback;

  /// {@macro flutter.material.popupmenu.mouseCursor}
  ///
  /// If specified, overrides the default value of [PopupMenuItem.mouseCursor].
  final MaterialStateProperty<MouseCursor?>? mouseCursor;

  /// Whether the popup menu is positioned over or under the popup menu button.
  ///
  /// When not set, the position defaults to [PopupMenuPosition.over] which makes the
  /// popup menu appear directly over the button that was used to create it.
  final PopupMenuPosition? position;

  /// The color of the icon in the popup menu button.
  final Color? iconColor;

  /// The size of the icon in the popup menu button.
  final double? iconSize;

  /// Creates a copy of this object with the given fields replaced with the
  /// new values.
  PopupMenuThemeData copyWith({
    Color? color,
    ShapeBorder? shape,
    double? elevation,
    Color? shadowColor,
    Color? surfaceTintColor,
    TextStyle? textStyle,
    MaterialStateProperty<TextStyle?>? labelTextStyle,
    bool? enableFeedback,
    MaterialStateProperty<MouseCursor?>? mouseCursor,
    PopupMenuPosition? position,
    Color? iconColor,
    double? iconSize,
  }) {
    return PopupMenuThemeData(
      color: color ?? this.color,
      shape: shape ?? this.shape,
      elevation: elevation ?? this.elevation,
      shadowColor: shadowColor ?? this.shadowColor,
      surfaceTintColor: surfaceTintColor ?? this.surfaceTintColor,
      textStyle: textStyle ?? this.textStyle,
      labelTextStyle: labelTextStyle ?? this.labelTextStyle,
      enableFeedback: enableFeedback ?? this.enableFeedback,
      mouseCursor: mouseCursor ?? this.mouseCursor,
      position: position ?? this.position,
      iconColor: iconColor ?? this.iconColor,
      iconSize: iconSize ?? this.iconSize,
    );
  }

  /// Linearly interpolate between two popup menu themes.
  ///
  /// If both arguments are null, then null is returned.
  ///
  /// {@macro dart.ui.shadow.lerp}
  static PopupMenuThemeData? lerp(PopupMenuThemeData? a, PopupMenuThemeData? b, double t) {
    if (identical(a, b)) {
      return a;
    }
    return PopupMenuThemeData(
      color: Color.lerp(a?.color, b?.color, t),
      shape: ShapeBorder.lerp(a?.shape, b?.shape, t),
      elevation: lerpDouble(a?.elevation, b?.elevation, t),
      shadowColor: Color.lerp(a?.shadowColor, b?.shadowColor, t),
      surfaceTintColor: Color.lerp(a?.surfaceTintColor, b?.surfaceTintColor, t),
      textStyle: TextStyle.lerp(a?.textStyle, b?.textStyle, t),
      labelTextStyle: MaterialStateProperty.lerp<TextStyle?>(a?.labelTextStyle, b?.labelTextStyle, t, TextStyle.lerp),
      enableFeedback: t < 0.5 ? a?.enableFeedback : b?.enableFeedback,
      mouseCursor: t < 0.5 ? a?.mouseCursor : b?.mouseCursor,
      position: t < 0.5 ? a?.position : b?.position,
      iconColor: Color.lerp(a?.iconColor, b?.iconColor, t),
      iconSize: lerpDouble(a?.iconSize, b?.iconSize, t),
    );
  }

  @override
  int get hashCode => Object.hash(
    color,
    shape,
    elevation,
    shadowColor,
    surfaceTintColor,
    textStyle,
    labelTextStyle,
    enableFeedback,
    mouseCursor,
    position,
    iconColor,
    iconSize,
  );

  @override
  bool operator ==(Object other) {
    if (identical(this, other)) {
      return true;
    }
    if (other.runtimeType != runtimeType) {
      return false;
    }
    return other is PopupMenuThemeData
        && other.color == color
        && other.shape == shape
        && other.elevation == elevation
        && other.shadowColor == shadowColor
        && other.surfaceTintColor == surfaceTintColor
        && other.textStyle == textStyle
        && other.labelTextStyle == labelTextStyle
        && other.enableFeedback == enableFeedback
        && other.mouseCursor == mouseCursor
        && other.position == position
        && other.iconColor == iconColor
        && other.iconSize == iconSize;
  }

  @override
  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
    super.debugFillProperties(properties);
    properties.add(ColorProperty('color', color, defaultValue: null));
    properties.add(DiagnosticsProperty<ShapeBorder>('shape', shape, defaultValue: null));
    properties.add(DoubleProperty('elevation', elevation, defaultValue: null));
    properties.add(ColorProperty('shadowColor', shadowColor, defaultValue: null));
    properties.add(ColorProperty('surfaceTintColor', surfaceTintColor, defaultValue: null));
    properties.add(DiagnosticsProperty<TextStyle>('text style', textStyle, defaultValue: null));
    properties.add(DiagnosticsProperty<MaterialStateProperty<TextStyle?>>('labelTextStyle', labelTextStyle, defaultValue: null));
    properties.add(DiagnosticsProperty<bool>('enableFeedback', enableFeedback, defaultValue: null));
    properties.add(DiagnosticsProperty<MaterialStateProperty<MouseCursor?>>('mouseCursor', mouseCursor, defaultValue: null));
    properties.add(EnumProperty<PopupMenuPosition?>('position', position, defaultValue: null));
    properties.add(ColorProperty('iconColor', iconColor, defaultValue: null));
    properties.add(DoubleProperty('iconSize', iconSize, defaultValue: null));
  }
}

/// An inherited widget that defines the configuration for
/// popup menus in this widget's subtree.
///
/// Values specified here are used for popup menu properties that are not
/// given an explicit non-null value.
class PopupMenuTheme extends InheritedTheme {
  /// Creates a popup menu theme that controls the configurations for
  /// popup menus in its widget subtree.
  const PopupMenuTheme({
    super.key,
    required this.data,
    required super.child,
  });

  /// The properties for descendant popup menu widgets.
  final PopupMenuThemeData data;

  /// The closest instance of this class's [data] value that encloses the given
  /// context. If there is no ancestor, it returns [ThemeData.popupMenuTheme].
  /// Applications can assume that the returned value will not be null.
  ///
  /// Typical usage is as follows:
  ///
  /// ```dart
  /// PopupMenuThemeData theme = PopupMenuTheme.of(context);
  /// ```
  static PopupMenuThemeData of(BuildContext context) {
    final PopupMenuTheme? popupMenuTheme = context.dependOnInheritedWidgetOfExactType<PopupMenuTheme>();
    return popupMenuTheme?.data ?? Theme.of(context).popupMenuTheme;
  }

  @override
  Widget wrap(BuildContext context, Widget child) {
    return PopupMenuTheme(data: data, child: child);
  }

  @override
  bool updateShouldNotify(PopupMenuTheme oldWidget) => data != oldWidget.data;
}